title: Malaria in the Greater Mekong Subregion: heterogeneity and complexity.
abstract: The Greater Mekong Subregion (GMS), comprised of six countries including Cambodia, China's Yunnan Province, Lao PDR, Myanmar (Burma), Thailand and Vietnam, is one of the most threatening foci of malaria. Since the initiation of the WHO's Mekong Malaria Program a decade ago, malaria situation in the GMS has greatly improved, reflected in the continuous decline in annual malaria incidence and deaths. However, as many nations are moving towards malaria elimination, the GMS nations still face great challenges. Malaria epidemiology in this region exhibits enormous geographical heterogeneity with Myanmar and Cambodia remaining high-burden countries. Within each country, malaria distribution is also patchy, exemplified by 'border malaria' and 'forest malaria' with high transmission occurring along international borders and in forests or forest fringes, respectively. 'Border malaria' is extremely difficult to monitor, and frequent malaria introductions by migratory human populations constitute a major threat to neighboring, malaria-eliminating countries. Therefore, coordination between neighboring countries is essential for malaria elimination from the entire region. In addition to these operational difficulties, malaria control in the GMS also encounters several technological challenges. Contemporary malaria control measures rely heavily on effective chemotherapy and insecticide control of vector mosquitoes. However, the spread of multidrug resistance and potential emergence of artemisinin resistance in Plasmodium falciparum make resistance management a high priority in the GMS. This situation is further worsened by the circulation of counterfeit and substandard artemisinin-related drugs. In most endemic areas of the GMS, P. falciparum and Plasmodium vivax coexist, and in recent malaria control history, P. vivax has demonstrated remarkable resilience to control measures. Deployment of the only registered drug (primaquine) for the radical cure of vivax malaria is severely undermined due to high prevalence of glucose-6-phosphate dehydrogenase deficiency in target human populations. In the GMS, the dramatically different ecologies, diverse vector systems, and insecticide resistance render traditional mosquito control less efficient. Here we attempt to review the changing malaria epidemiology in the GMS, analyze the vector systems and patterns of malaria transmission, and identify the major challenges the malaria control community faces on its way to malaria elimination.
authors.affiliation: Department of Entomology, The Pennsylvania State University, University Park, 16801, USA. luc2@psu.edu
authors.forename: Liwang
authors.initials: L
authors.lastname: Cui
authors.forename: Guiyun
authors.initials: G
authors.lastname: Yan
authors.forename: Jetsumon
authors.initials: J
authors.lastname: Sattabongkot
authors.forename: Yaming
authors.initials: Y
authors.lastname: Cao
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Chen
authors.forename: Qi
authors.initials: Q
authors.lastname: Fan
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fang
authors.forename: Somchai
authors.initials: S
authors.lastname: Jongwutiwes
authors.forename: Daniel
authors.initials: D
authors.lastname: Parker
authors.forename: Jeeraphat
authors.initials: J
authors.lastname: Sirichaisinthop
authors.forename: Myat Phone
authors.initials: MP
authors.lastname: Kyaw
authors.forename: Xin-zhuan
authors.initials: XZ
authors.lastname: Su
authors.forename: Henglin
authors.initials: H
authors.lastname: Yang
authors.forename: Zhaoqing
authors.initials: Z
authors.lastname: Yang
authors.forename: Baomin
authors.initials: B
authors.lastname: Wang
authors.forename: Jianwei
authors.initials: J
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Zheng
authors.forename: Daibin
authors.initials: D
authors.lastname: Zhong
authors.forename: Guofa
authors.initials: G
authors.lastname: Zhou
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects / Q000235:genetics / Q000469:parasitology; D000962:Antimalarials / Q000494:pharmacology; D001210:Asia, Southeastern / Q000453:epidemiology; D060740:Disease Eradication / Q000379:methods*; D018432:Drug Resistance, Multiple; D006801:Humans; D007303:Insect Vectors / Q000187:drug effects / Q000235:genetics / Q000469:parasitology; D007305:Insecticide Resistance; D057148:Insecticide-Treated Bednets; D007391:International Cooperation; D008288:Malaria / Q000188:drug therapy / Q000453:epidemiology / Q000469:parasitology / Q000517:prevention & control*; D009032:Mosquito Control / Q000379:methods*; D010961:Plasmodium / Q000472:pathogenicity*; D011722:Pyrethrins / Q000494:pharmacology
chemical_list: D000962:Antimalarials; D011722:Pyrethrins